A printed circuit board inspection system
By combining light source devices and optical components, and utilizing the differences in photosensitive characteristics of white substrates and metals under different light sources, clear printed circuit board images are generated, solving the problems of low detection accuracy and efficiency of substrate and metal areas, and achieving high-precision area differentiation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- POLAR LIGHT TECH CO LTD
- Filing Date
- 2025-04-16
- Publication Date
- 2026-05-29
Smart Images
Figure CN224303596U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of printed circuit board testing technology, and in particular to a printed circuit board testing system. Background Technology
[0002] In the inspection and manufacturing process of printed circuit boards (PCBs), accurately distinguishing between the substrate area and the metal area is crucial for identifying defects in the metal area and ensuring PCB quality. Current technologies typically rely on image recognition of the PCB to distinguish between the substrate and metal areas. However, protrusions exist in the metal area of PCBs, which appear as shadows in the image, reducing the accuracy and efficiency of area detection. Furthermore, with the increasing demand for high-frequency circuit boards, white substrates are widely used. The imaging characteristics of white substrates and metal under white light are similar, making it difficult to effectively distinguish between the substrate and metal areas of the PCB. Utility Model Content
[0003] This invention provides a printed circuit board inspection system to solve the problems of poor accuracy and low efficiency when inspecting the substrate area and metal area of printed circuit boards.
[0004] According to one aspect of the present invention, a testing system for printed circuit boards is provided. The system includes: a light source device, a beam splitter, a first reflector, a second reflector, a first plano-convex lens, a second plano-convex lens, a third plano-convex lens, a carrier plate, and an imaging device. The normals of the beam splitter, the first reflector, and the second reflector are not parallel to each other. The carrier plate is used to place the printed circuit board.
[0005] The light source device emits a first beam, a second beam, and a third beam;
[0006] The first beam passes sequentially through the plane and convex surface of the first plano-convex lens and is transmitted to the beam splitter. After being reflected by the beam splitter, it illuminates the preset area of the carrier plate.
[0007] The second beam passes through the plane of the second plano-convex lens and the convex surface of the second plano-convex lens in sequence, and is transmitted to the first reflecting mirror. After being reflected by the first reflecting mirror again, it illuminates the preset area of the carrier plate.
[0008] The third beam passes through the plane of the third plano-convex lens and the convex surface of the third plano-convex lens in sequence, and is transmitted to the second reflector. After being reflected by the second reflector again, it illuminates the preset area of the carrier plate.
[0009] The first, second, and third beams are reflected by a preset area on the carrier plate and then transmitted through the beam splitter to the imaging device.
[0010] Optionally, the light source device is a light-emitting diode that emits white light or ultraviolet light.
[0011] Optionally, the wavelength of the ultraviolet light is 365nm.
[0012] Optionally, the system further includes: a first optical fiber, a second optical fiber, and a third optical fiber, wherein the light emitted by the light source device is coupled to a first end of the first optical fiber, a first end of the second optical fiber, and a first end of the third optical fiber, a first beam is emitted from the second end of the first optical fiber, a second beam is emitted from the second end of the second optical fiber, and a third beam is emitted from the second end of the third optical fiber.
[0013] Optionally, the system also includes: a heat-insulating filter, through which light emitted by the light source device is coupled to the first end of the first optical fiber, the first end of the second optical fiber, and the first end of the third optical fiber.
[0014] Optionally, the system also includes: a filter, wherein light emitted by the light source device passes through the filter and is coupled to the first end of the first optical fiber, the first end of the second optical fiber, and the first end of the third optical fiber.
[0015] Optionally, the system may also include: a fourth plano-convex lens and a fifth plano-convex lens;
[0016] After being reflected by the first reflector, the second beam passes through the convex surface of the fourth plano-convex lens and the plane of the fourth plano-convex lens in sequence before being transmitted to the preset area of the carrier plate.
[0017] After being reflected by the second mirror, the third beam passes sequentially through the convex surface of the fifth plano-convex lens and the flat surface of the fifth plano-convex lens before being transmitted to the preset area of the carrier plate.
[0018] Optionally, the first beam is reflected by a beam splitter and then vertically illuminates a preset area of the carrier plate.
[0019] Optionally, the imaging device is a line scan camera.
[0020] Optionally, a line scan camera includes an aperture, lenses, and charge-coupled devices.
[0021] The technical solution of this utility model embodiment involves a light source device emitting a first beam, a second beam, and a third beam. The first beam passes sequentially through the plane and convex surface of a first plano-convex lens and is transmitted to a beam splitter, then reflected by the beam splitter and illuminates a preset area of a carrier plate. The second beam passes sequentially through the plane and convex surface of a second plano-convex lens and is transmitted to a first reflecting mirror, then reflected by the first reflecting mirror and illuminates a preset area of the carrier plate. The third beam passes sequentially through the plane and convex surface of a third plano-convex lens and is transmitted to a second reflecting mirror, then reflected by the second reflecting mirror and illuminates a preset area of the carrier plate. The first, second, and third beams are reflected by the preset area of the carrier plate and then transmitted from the beam splitter to the imaging device. This solution enables the first, second, and third beams to illuminate a preset area of the carrier plate from different angles, so that the printed circuit board placed in the preset area of the carrier plate can be fully covered by the beams. As a result, the imaging device can generate a clear image of the printed circuit board placed in the preset area of the carrier plate based on the incident first, second, and third beams, so as to display the raised parts of the printed circuit board in the image, thereby accurately distinguishing the substrate area and the metal area in the image.
[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 A schematic diagram of the structure of a printed circuit board testing system provided in an embodiment of this utility model;
[0025] Figure 2 A schematic diagram of another printed circuit board testing system provided in an embodiment of this utility model;
[0026] Figure 3 A schematic diagram of the structure of another printed circuit board testing system provided in this embodiment of the present utility model;
[0027] Figure 4 A schematic diagram of the structure of another printed circuit board testing system provided in this embodiment of the present utility model;
[0028] Figure 5 This is a schematic diagram of a printed circuit board testing system provided as an embodiment of the present invention. Detailed Implementation
[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0031] Figure 1 This is a schematic diagram of a printed circuit board inspection system provided by an embodiment of the present invention. This embodiment of the present invention is applicable to situations where the substrate area and metal area of a printed circuit board need to be distinguished. Figure 1 As shown, the printed circuit board inspection system includes: a light source device 100, a beam splitter 200, a first reflector 300, a second reflector 400, a first plano-convex lens 500, a second plano-convex lens 600, a third plano-convex lens 700, a carrier plate 800, and an imaging device 900. The normals of the beam splitter 200, the first reflector 300, and the second reflector 400 are not parallel to each other. The carrier plate 800 is used to place the printed circuit board.
[0032] The light source device 100 emits a first beam, a second beam, and a third beam;
[0033] The first beam passes through the plane and the convex surface of the first plano-convex lens 500 in sequence and is transmitted to the beam splitter 200. After being reflected by the beam splitter 200, it illuminates the preset area of the carrier plate 800.
[0034] The second beam passes through the plane and the convex surface of the second plano-convex lens 600 in sequence and is transmitted to the first reflector 300. After being reflected by the first reflector 300 again, it illuminates the preset area of the carrier plate 800.
[0035] The third beam passes through the plane and the convex surface of the third plano-convex lens 700 in sequence and is transmitted to the second reflector 400. After being reflected by the second reflector 400 again, it illuminates the preset area of the carrier plate 800.
[0036] The first beam, the second beam, and the third beam are reflected by the preset area of the carrier plate 800 and then transmitted from the beam splitter 200 to the imaging device 900.
[0037] In this embodiment of the invention, a printed circuit board (PCB) can refer to a circuit board containing conductive lines, manufactured according to a predetermined design using an insulating board as a substrate. The printed circuit board achieves electrical connections between electronic components by printing conductive lines on the substrate. The metal area of the printed circuit board may include the conductive lines printed on the insulating substrate.
[0038] The light source device 100 can refer to a device that emits a light beam to a predetermined area of the carrier plate 800. The light source device 100 can achieve the emission of a light beam by converting an electrical signal into an optical signal. For example, the light source device 100 can consist of two spotlight bulbs. The predetermined area of the carrier plate 800 can refer to a pre-defined area for placing a printed circuit board. The beam splitter 200 can refer to a semi-reflective mirror. The beam splitter 200 can be made by depositing a specific optical thin film on the surface of an optical material. Half of the light beam incident on the beam splitter 200 is reflected by the beam splitter 200, and the other half is transmitted by the beam splitter 200. The plano-convex lens can be an optical lens having a flat surface and a convex surface. Parallel light beams converge at the focal point of the plano-convex lens after passing through it. Similarly, diverging light beams emitted from the focal point of the plano-convex lens become parallel light beams after passing through it.
[0039] Specifically, the light source device 100 can sequentially emit a first beam, a second beam, and a third beam from the focal positions of the first plano-convex lens 500, the second plano-convex lens 600, and the third plano-convex lens 700, respectively, located on one side of the plane. This ensures that the first beam emitted by the light source device 100 becomes a parallel beam after transmission through the first plano-convex lens 500, the second beam becomes a parallel beam after transmission through the second plano-convex lens 600, and the third beam becomes a parallel beam after transmission through the third plano-convex lens 700. This allows the first, second, and third beams to stably illuminate a predetermined area of the carrier plate 800. The focal positions of the first plano-convex lens 500, the second plano-convex lens 600, and the third plano-convex lens 700, located on one side of the plane, can be arranged in a triangular pattern, with the focal position of the first plano-convex lens 500 higher than the focal positions of the second plano-convex lenses 600 and 700.
[0040] The imaging device 900 can generate an image of a printed circuit board placed in a predetermined area of the carrier plate 800 based on a first beam, a second beam, and a third beam incident on the imaging device 900. Furthermore, after performing predetermined image processing on the image generated by the imaging device 900, it is possible to distinguish between substrate areas and metal areas in the image generated by the imaging device 900, thereby further identifying and analyzing whether there are defects in the printed circuit board placed in the predetermined area of the carrier plate 800. The predetermined image processing may include at least: noise reduction, grayscale conversion, and segmentation. For example, after performing predetermined image processing on the image generated by the imaging device 900, pixels within a predetermined grayscale value range in the image can be classified as substrate areas, and pixels outside the predetermined grayscale value range in the image can be classified as metal areas.
[0041] The normals of the beam splitter 200, the first reflector 300, and the second reflector 400 are not parallel to each other. This allows the first beam reflected by the beam splitter 200, the second beam reflected by the first reflector 300, and the third beam reflected by the second reflector 400 to illuminate the preset area of the carrier plate 800 from different angles. The second and third beams can then provide supplementary lighting to effectively identify the protruding parts of the printed circuit board placed in the preset area of the carrier plate 800.
[0042] As an optional embodiment of this utility model, the light source device 100 is a light-emitting diode that emits white light or ultraviolet light.
[0043] In this embodiment of the invention, when the substrate of the printed circuit board placed in the preset area of the carrier plate 800 is a white substrate, the light source device 100 uses an ultraviolet light-emitting diode (UV-LED). This avoids the situation where the imaging characteristics of the white substrate and the metal are similar under white light. Based on the different photosensitive characteristics of the white substrate and the metal under ultraviolet light, it can distinguish the white substrate area and the metal area in the image of the printed circuit board placed in the preset area of the carrier plate 800. When the substrate of the printed circuit board placed in the preset area of the carrier plate 800 is a non-white substrate, the light source device 100 can use a white light-emitting diode.
[0044] As an optional embodiment of this utility model, the wavelength of ultraviolet light is 365nm, so as to improve the photosensitivity of the white substrate under ultraviolet light, thereby improving the accuracy of distinguishing the white substrate area and the metal area in the image of the printed circuit board placed in the preset area of the carrier board 800.
[0045] As an optional embodiment of this utility model, refer to Figure 2 The printed circuit board inspection system also includes: a first optical fiber 110, a second optical fiber 120 and a third optical fiber 130. The light emitted by the light source device 100 is coupled to the first end 111 of the first optical fiber 110, the first end 121 of the second optical fiber 120 and the first end 131 of the third optical fiber 130. The second end 112 of the first optical fiber 110 emits a first beam, the second end 122 of the second optical fiber 120 emits a second beam, and the second end 132 of the third optical fiber 130 emits a third beam.
[0046] In this embodiment of the invention, the optical fiber can refer to a fiber made of glass or plastic. The optical fiber achieves efficient transmission of a light beam based on total internal reflection. The second end 112 of the first optical fiber 110, the second end 122 of the second optical fiber 120, and the second end 132 of the third optical fiber 130 are located at different outlet positions, thereby enabling the transmission of light emitted by the light source device 100 through the first optical fiber 110, the second optical fiber 120, and the third optical fiber 130, thus improving the light transmission efficiency.
[0047] As an optional embodiment of this utility model, refer to Figure 3 The printed circuit board testing system also includes a heat-insulating filter 140, through which light emitted by the light source device 100 is coupled to the first end 111 of the first optical fiber 110, the first end 121 of the second optical fiber 120 and the first end 131 of the third optical fiber 130.
[0048] In this embodiment of the invention, the heat-insulating filter 140 can be used to isolate the heat generated by the light source device 100 when emitting light, so as to prevent the heat generated by the light source device 100 from damaging the first optical fiber 110, the second optical fiber 120 and the third optical fiber 130.
[0049] As an optional embodiment of this utility model, the printed circuit board detection system further includes: a filter, wherein the light emitted by the light source device 100 passes through the filter and is coupled to the first end 111 of the first optical fiber 110, the first end 121 of the second optical fiber 120 and the first end 131 of the third optical fiber 130.
[0050] In this embodiment of the invention, the filter can be used to transmit light within a preset wavelength range emitted by the light source device 100, so that the first beam emitted from the first optical fiber 110, the second beam emitted from the second optical fiber 120, and the third beam emitted from the third optical fiber 130 can detect printed circuit boards of different substrate types, thereby improving the application range of the printed circuit board detection system. For example, the filter can be configured to transmit red light, adapting to printed circuit boards that are detected using red light.
[0051] As an optional embodiment of this utility model, refer to Figure 4 The printed circuit board inspection system also includes: a fourth plano-convex lens 150 and a fifth plano-convex lens 160;
[0052] After being reflected by the first reflecting mirror 300, the second beam passes through the convex surface of the fourth plano-convex lens 150 and the plane of the fourth plano-convex lens 150 in sequence before being transmitted to the preset area of the carrier plate 800.
[0053] After being reflected by the second reflector 400, the third beam passes through the convex surface of the fifth plano-convex lens 160 and the plane of the fifth plano-convex lens 160 in sequence before being transmitted to the preset area of the carrier plate 800.
[0054] In this embodiment of the invention, the fourth plano-convex lens 150 can be used to focus the second beam reflected by the first reflecting mirror 300. The fifth plano-convex lens 160 can be used to focus the third beam reflected by the second reflecting mirror 400. After the second and third beams are focused, they illuminate a preset area of the carrier plate 800, which can enhance the brightness of the beam illuminating the printed circuit board placed in the preset area of the carrier plate 800, so as to ensure that the beam brightness meets the requirements of the imaging device 900, thereby improving the image clarity of the printed circuit board.
[0055] As an optional embodiment of this utility model, the first beam is reflected by the beam splitter 200 and then vertically illuminates a preset area of the carrier plate 800, so that the first beam can fully cover the printed circuit board placed in the preset area of the carrier plate 800, ensuring the integrity of the image on the printed circuit board.
[0056] As an optional embodiment of this utility model, the imaging device 900 is a line scan camera.
[0057] In this embodiment of the invention, the line scan camera refers to a camera that uses a linear photosensitive element to scan line by line to acquire images of a printed circuit board placed in a preset area of a carrier board 800. The line scan camera captures one row of pixels from the printed circuit board each time, and as the line scan camera or the printed circuit board moves to capture images, the continuously captured rows of pixels are stitched together to form a two-dimensional image of the printed circuit board. By using a line scan camera as the imaging device 900, the efficiency of acquiring images of the printed circuit board can be ensured.
[0058] As an optional embodiment of this utility model, refer to Figure 5 The line scan camera includes an aperture 901, a lens 902, and a charge-coupled device 903.
[0059] In this embodiment of the invention, the light beam entering the line scan camera passes sequentially through aperture 901 and lens 902 before being focused onto charge-coupled device 903. The focused beam is then converted into an electrical signal by the charge-coupled device 903, thereby generating an image of the printed circuit board based on the converted electrical signal. The light beam entering the line scan camera includes a first beam, a second beam, and a third beam transmitted through beam splitter 200. Adjusting the size of aperture 901 controls the intensity of the light beam entering the line scan camera, ensuring uniform brightness of the printed circuit board image. Lens 902 focuses the light beam, improving the resolution and contrast of the printed circuit board image. The charge-coupled device 903 (CCD) of the line scan camera has a linear array structure, enabling line-by-line scanning of the printed circuit board placed in a preset area of the carrier board 800.
[0060] The technical solution of this utility model embodiment involves a light source device emitting a first beam, a second beam, and a third beam. The first beam passes sequentially through the plane and convex surface of a first plano-convex lens and is transmitted to a beam splitter, then reflected by the beam splitter and illuminates a preset area of a carrier plate. The second beam passes sequentially through the plane and convex surface of a second plano-convex lens and is transmitted to a first reflecting mirror, then reflected by the first reflecting mirror and illuminates a preset area of the carrier plate. The third beam passes sequentially through the plane and convex surface of a third plano-convex lens and is transmitted to a second reflecting mirror, then reflected by the second reflecting mirror and illuminates a preset area of the carrier plate. The first, second, and third beams are reflected by the preset area of the carrier plate and then transmitted from the beam splitter to the imaging device. This solution enables the first, second, and third beams to illuminate a preset area of the carrier plate from different angles, so that the printed circuit board placed in the preset area of the carrier plate can be fully covered by the beams. As a result, the imaging device can generate a clear image of the printed circuit board placed in the preset area of the carrier plate based on the incident first, second, and third beams, so as to display the raised parts of the printed circuit board in the image, thereby accurately distinguishing the substrate area and the metal area in the image.
[0061] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.
[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A testing system for printed circuit boards, characterized in that, include: The device includes a light source, a beam splitter, a first reflector, a second reflector, a first plano-convex lens, a second plano-convex lens, a third plano-convex lens, a carrier plate, and an imaging device. The normals of the beam splitter, the first reflector, and the second reflector are not parallel to each other. The carrier plate is used to place a printed circuit board. The light source device emits a first beam, a second beam, and a third beam; The first beam passes sequentially through the plane of the first plano-convex lens and the convex surface of the first plano-convex lens before being transmitted to the beam splitter. After being reflected again by the beam splitter, it illuminates the preset area of the carrier plate. The second beam passes sequentially through the plane of the second plano-convex lens and the convex surface of the second plano-convex lens before being transmitted to the first reflector. After being reflected again by the first reflector, it illuminates the preset area of the carrier plate. The third beam passes sequentially through the plane of the third plano-convex lens and the convex surface of the third plano-convex lens before being transmitted to the second reflector. After being reflected again by the second reflector, it illuminates the preset area of the carrier plate. The first beam, the second beam, and the third beam are reflected by a preset area of the carrier plate and then transmitted from the beam splitter to the imaging device.
2. The system according to claim 1, characterized in that, The light source device is a light-emitting diode that emits white light or ultraviolet light.
3. The system according to claim 2, characterized in that, The wavelength of the ultraviolet light is 365nm.
4. The system according to claim 1, characterized in that, The system further includes a first optical fiber, a second optical fiber, and a third optical fiber. The light emitted by the light source device is coupled to a first end of the first optical fiber, a first end of the second optical fiber, and a first end of the third optical fiber. A first light beam is emitted from a second end of the first optical fiber, a second light beam is emitted from a second end of the second optical fiber, and a third light beam is emitted from a second end of the third optical fiber.
5. The system according to claim 4, characterized in that, The system further includes a heat-insulating filter, wherein the light emitted by the light source device passes through the heat-insulating filter and is coupled to the first end of the first optical fiber, the first end of the second optical fiber, and the first end of the third optical fiber.
6. The system according to claim 4, characterized in that, The system further includes a filter, wherein light emitted by the light source device passes through the filter and is coupled to a first end of the first optical fiber, a first end of the second optical fiber, and a first end of the third optical fiber.
7. The system according to claim 1, characterized in that, The system also includes: a fourth plano-convex lens and a fifth plano-convex lens; After being reflected by the first reflector, the second beam passes sequentially through the convex surface of the fourth plano-convex lens and the plane of the fourth plano-convex lens before being transmitted to the preset area of the carrier plate. The third beam, after being reflected by the second reflector, passes sequentially through the convex surface of the fifth plano-convex lens and the plane of the fifth plano-convex lens before being transmitted to the preset area of the carrier plate.
8. The system according to claim 1, characterized in that, The first beam is reflected by the beam splitter and then vertically illuminates a predetermined area of the carrier plate.
9. The system according to claim 1, characterized in that, The imaging device is a line scan camera.
10. The system according to claim 9, characterized in that, The line scan camera includes an aperture, a lens, and a charge-coupled device.